The present invention relates to an immersion or submerged nozzle, particularly for use in casting of thin slab articles, further particularly for such casting from molten metal. The present invention further relates to such a nozzle including an upper section to be attached to or mounted on a vessel, for example a metallurgical vessel, and a lower section having a region to be immersed or submerged in casting material within a mold. Further particularly, the present invention relates to such a nozzle wherein the upper and lower sections have extending therethrough respective discharge channels that communicate and enable material, particularly molten metal, to be discharged from the vessel to the mold, and wherein the discharge channel of the upper section tapers downwardly in a first vertical plane to join the discharge channel of the lower section, and the discharge channel of the upper section also expands or widens downwardly in a second vertical plane transverse to the first vertical plane to join the discharge channel of the lower section.
An immersion nozzle of the above general type is disclosed in DE 37 09 188 A1. Such nozzle is divided into separate longitudinal sections that may be made of different materials. Nevertheless however, the nozzle is constructed as a one-piece component. The manufacture of such nozzle is expensive, and when one section thereof becomes worn, the entire nozzle has to be replaced as an entire unit.
DE 40 24 520 C2, corresponding to U.S. Pat. No. 5,173,242, discloses a manner of connection between an outlet member of a metallurgical vessel and an immersion nozzle having a lower section to be immersed within molten material in a mold. At a region of a seat between the immersion nozzle and the outlet, a concentric annular chamber or channel is provided, with an inert gas feed pipe leading to such chamber. Compressible rings are positioned as sealing rings both above and below the annular chamber. The inert gas feed pipe has a pressure indicator to read the gas pressure within the annular chamber. If a leak occurs at one of the sealing rings, the pressure drops, and the indicator provides an indication of such pressure drop.